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      1 /*
      2  * EAP peer method: EAP-TLS (RFC 2716)
      3  * Copyright (c) 2004-2008, 2012, Jouni Malinen <j (at) w1.fi>
      4  *
      5  * This software may be distributed under the terms of the BSD license.
      6  * See README for more details.
      7  */
      8 
      9 #include "includes.h"
     10 
     11 #include "common.h"
     12 #include "crypto/tls.h"
     13 #include "eap_i.h"
     14 #include "eap_tls_common.h"
     15 #include "eap_config.h"
     16 
     17 
     18 static void eap_tls_deinit(struct eap_sm *sm, void *priv);
     19 
     20 
     21 struct eap_tls_data {
     22 	struct eap_ssl_data ssl;
     23 	u8 *key_data;
     24 	void *ssl_ctx;
     25 	u8 eap_type;
     26 };
     27 
     28 
     29 static void * eap_tls_init(struct eap_sm *sm)
     30 {
     31 	struct eap_tls_data *data;
     32 	struct eap_peer_config *config = eap_get_config(sm);
     33 	if (config == NULL ||
     34 	    ((sm->init_phase2 ? config->private_key2 : config->private_key)
     35 	     == NULL &&
     36 	     (sm->init_phase2 ? config->engine2 : config->engine) == 0)) {
     37 		wpa_printf(MSG_INFO, "EAP-TLS: Private key not configured");
     38 		return NULL;
     39 	}
     40 
     41 	data = os_zalloc(sizeof(*data));
     42 	if (data == NULL)
     43 		return NULL;
     44 
     45 	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
     46 		sm->ssl_ctx;
     47 
     48 	if (eap_peer_tls_ssl_init(sm, &data->ssl, config, EAP_TYPE_TLS)) {
     49 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
     50 		eap_tls_deinit(sm, data);
     51 		if (config->engine) {
     52 			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting Smartcard "
     53 				   "PIN");
     54 			eap_sm_request_pin(sm);
     55 			sm->ignore = TRUE;
     56 		} else if (config->private_key && !config->private_key_passwd)
     57 		{
     58 			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting private "
     59 				   "key passphrase");
     60 			eap_sm_request_passphrase(sm);
     61 			sm->ignore = TRUE;
     62 		}
     63 		return NULL;
     64 	}
     65 
     66 	data->eap_type = EAP_TYPE_TLS;
     67 
     68 	return data;
     69 }
     70 
     71 
     72 #ifdef EAP_UNAUTH_TLS
     73 static void * eap_unauth_tls_init(struct eap_sm *sm)
     74 {
     75 	struct eap_tls_data *data;
     76 	struct eap_peer_config *config = eap_get_config(sm);
     77 
     78 	data = os_zalloc(sizeof(*data));
     79 	if (data == NULL)
     80 		return NULL;
     81 
     82 	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
     83 		sm->ssl_ctx;
     84 
     85 	if (eap_peer_tls_ssl_init(sm, &data->ssl, config,
     86 				  EAP_UNAUTH_TLS_TYPE)) {
     87 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
     88 		eap_tls_deinit(sm, data);
     89 		return NULL;
     90 	}
     91 
     92 	data->eap_type = EAP_UNAUTH_TLS_TYPE;
     93 
     94 	return data;
     95 }
     96 #endif /* EAP_UNAUTH_TLS */
     97 
     98 
     99 static void eap_tls_deinit(struct eap_sm *sm, void *priv)
    100 {
    101 	struct eap_tls_data *data = priv;
    102 	if (data == NULL)
    103 		return;
    104 	eap_peer_tls_ssl_deinit(sm, &data->ssl);
    105 	os_free(data->key_data);
    106 	os_free(data);
    107 }
    108 
    109 
    110 static struct wpabuf * eap_tls_failure(struct eap_sm *sm,
    111 				       struct eap_tls_data *data,
    112 				       struct eap_method_ret *ret, int res,
    113 				       struct wpabuf *resp, u8 id)
    114 {
    115 	wpa_printf(MSG_DEBUG, "EAP-TLS: TLS processing failed");
    116 
    117 	ret->methodState = METHOD_DONE;
    118 	ret->decision = DECISION_FAIL;
    119 
    120 	if (res == -1) {
    121 		struct eap_peer_config *config = eap_get_config(sm);
    122 		if (config) {
    123 			/*
    124 			 * The TLS handshake failed. So better forget the old
    125 			 * PIN. It may be wrong, we cannot be sure but trying
    126 			 * the wrong one again might block it on the card--so
    127 			 * better ask the user again.
    128 			 */
    129 			os_free(config->pin);
    130 			config->pin = NULL;
    131 		}
    132 	}
    133 
    134 	if (resp) {
    135 		/*
    136 		 * This is likely an alert message, so send it instead of just
    137 		 * ACKing the error.
    138 		 */
    139 		return resp;
    140 	}
    141 
    142 	return eap_peer_tls_build_ack(id, data->eap_type, 0);
    143 }
    144 
    145 
    146 static void eap_tls_success(struct eap_sm *sm, struct eap_tls_data *data,
    147 			    struct eap_method_ret *ret)
    148 {
    149 	wpa_printf(MSG_DEBUG, "EAP-TLS: Done");
    150 
    151 	ret->methodState = METHOD_DONE;
    152 	ret->decision = DECISION_UNCOND_SUCC;
    153 
    154 	os_free(data->key_data);
    155 	data->key_data = eap_peer_tls_derive_key(sm, &data->ssl,
    156 						 "client EAP encryption",
    157 						 EAP_TLS_KEY_LEN +
    158 						 EAP_EMSK_LEN);
    159 	if (data->key_data) {
    160 		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived key",
    161 				data->key_data, EAP_TLS_KEY_LEN);
    162 		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived EMSK",
    163 				data->key_data + EAP_TLS_KEY_LEN,
    164 				EAP_EMSK_LEN);
    165 	} else {
    166 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to derive key");
    167 	}
    168 }
    169 
    170 
    171 static struct wpabuf * eap_tls_process(struct eap_sm *sm, void *priv,
    172 				       struct eap_method_ret *ret,
    173 				       const struct wpabuf *reqData)
    174 {
    175 	size_t left;
    176 	int res;
    177 	struct wpabuf *resp;
    178 	u8 flags, id;
    179 	const u8 *pos;
    180 	struct eap_tls_data *data = priv;
    181 
    182 	pos = eap_peer_tls_process_init(sm, &data->ssl, data->eap_type, ret,
    183 					reqData, &left, &flags);
    184 	if (pos == NULL)
    185 		return NULL;
    186 	id = eap_get_id(reqData);
    187 
    188 	if (flags & EAP_TLS_FLAGS_START) {
    189 		wpa_printf(MSG_DEBUG, "EAP-TLS: Start");
    190 		left = 0; /* make sure that this frame is empty, even though it
    191 			   * should always be, anyway */
    192 	}
    193 
    194 	resp = NULL;
    195 	res = eap_peer_tls_process_helper(sm, &data->ssl, data->eap_type, 0,
    196 					  id, pos, left, &resp);
    197 
    198 	if (res < 0) {
    199 		return eap_tls_failure(sm, data, ret, res, resp, id);
    200 	}
    201 
    202 	if (tls_connection_established(data->ssl_ctx, data->ssl.conn))
    203 		eap_tls_success(sm, data, ret);
    204 
    205 	if (res == 1) {
    206 		wpabuf_free(resp);
    207 		return eap_peer_tls_build_ack(id, data->eap_type, 0);
    208 	}
    209 
    210 	return resp;
    211 }
    212 
    213 
    214 static Boolean eap_tls_has_reauth_data(struct eap_sm *sm, void *priv)
    215 {
    216 	struct eap_tls_data *data = priv;
    217 	return tls_connection_established(data->ssl_ctx, data->ssl.conn);
    218 }
    219 
    220 
    221 static void eap_tls_deinit_for_reauth(struct eap_sm *sm, void *priv)
    222 {
    223 }
    224 
    225 
    226 static void * eap_tls_init_for_reauth(struct eap_sm *sm, void *priv)
    227 {
    228 	struct eap_tls_data *data = priv;
    229 	os_free(data->key_data);
    230 	data->key_data = NULL;
    231 	if (eap_peer_tls_reauth_init(sm, &data->ssl)) {
    232 		os_free(data);
    233 		return NULL;
    234 	}
    235 	return priv;
    236 }
    237 
    238 
    239 static int eap_tls_get_status(struct eap_sm *sm, void *priv, char *buf,
    240 			      size_t buflen, int verbose)
    241 {
    242 	struct eap_tls_data *data = priv;
    243 	return eap_peer_tls_status(sm, &data->ssl, buf, buflen, verbose);
    244 }
    245 
    246 
    247 static Boolean eap_tls_isKeyAvailable(struct eap_sm *sm, void *priv)
    248 {
    249 	struct eap_tls_data *data = priv;
    250 	return data->key_data != NULL;
    251 }
    252 
    253 
    254 static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
    255 {
    256 	struct eap_tls_data *data = priv;
    257 	u8 *key;
    258 
    259 	if (data->key_data == NULL)
    260 		return NULL;
    261 
    262 	key = os_malloc(EAP_TLS_KEY_LEN);
    263 	if (key == NULL)
    264 		return NULL;
    265 
    266 	*len = EAP_TLS_KEY_LEN;
    267 	os_memcpy(key, data->key_data, EAP_TLS_KEY_LEN);
    268 
    269 	return key;
    270 }
    271 
    272 
    273 static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
    274 {
    275 	struct eap_tls_data *data = priv;
    276 	u8 *key;
    277 
    278 	if (data->key_data == NULL)
    279 		return NULL;
    280 
    281 	key = os_malloc(EAP_EMSK_LEN);
    282 	if (key == NULL)
    283 		return NULL;
    284 
    285 	*len = EAP_EMSK_LEN;
    286 	os_memcpy(key, data->key_data + EAP_TLS_KEY_LEN, EAP_EMSK_LEN);
    287 
    288 	return key;
    289 }
    290 
    291 
    292 int eap_peer_tls_register(void)
    293 {
    294 	struct eap_method *eap;
    295 	int ret;
    296 
    297 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
    298 				    EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
    299 	if (eap == NULL)
    300 		return -1;
    301 
    302 	eap->init = eap_tls_init;
    303 	eap->deinit = eap_tls_deinit;
    304 	eap->process = eap_tls_process;
    305 	eap->isKeyAvailable = eap_tls_isKeyAvailable;
    306 	eap->getKey = eap_tls_getKey;
    307 	eap->get_status = eap_tls_get_status;
    308 	eap->has_reauth_data = eap_tls_has_reauth_data;
    309 	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
    310 	eap->init_for_reauth = eap_tls_init_for_reauth;
    311 	eap->get_emsk = eap_tls_get_emsk;
    312 
    313 	ret = eap_peer_method_register(eap);
    314 	if (ret)
    315 		eap_peer_method_free(eap);
    316 	return ret;
    317 }
    318 
    319 
    320 #ifdef EAP_UNAUTH_TLS
    321 int eap_peer_unauth_tls_register(void)
    322 {
    323 	struct eap_method *eap;
    324 	int ret;
    325 
    326 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
    327 				    EAP_VENDOR_UNAUTH_TLS,
    328 				    EAP_VENDOR_TYPE_UNAUTH_TLS, "UNAUTH-TLS");
    329 	if (eap == NULL)
    330 		return -1;
    331 
    332 	eap->init = eap_unauth_tls_init;
    333 	eap->deinit = eap_tls_deinit;
    334 	eap->process = eap_tls_process;
    335 	eap->isKeyAvailable = eap_tls_isKeyAvailable;
    336 	eap->getKey = eap_tls_getKey;
    337 	eap->get_status = eap_tls_get_status;
    338 	eap->has_reauth_data = eap_tls_has_reauth_data;
    339 	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
    340 	eap->init_for_reauth = eap_tls_init_for_reauth;
    341 	eap->get_emsk = eap_tls_get_emsk;
    342 
    343 	ret = eap_peer_method_register(eap);
    344 	if (ret)
    345 		eap_peer_method_free(eap);
    346 	return ret;
    347 }
    348 #endif /* EAP_UNAUTH_TLS */
    349